Die mechanism



Oct. 16, 1934. R. Li wlLcox I 1,977,163

DIE MECHANISM Filed July 22, 1933 2 Sheets-Sheet l INVENTOR. file/MR0 55m? WILCOX Patented Oct. 16, 1934 DIE MECHANISM Richard Lester Wilcox, Waterbury, Conn., as-

signor to The Waterbury Farrel Foundry and Machine Company, Waterbury, Conn, a corporation of Connecticut Application July 22, 1933, Serial No. 681,745 15 Claims. (01. 10 -85) This invention relates to die mechanism, more particularly to that type of such mechanism as is used for piercing a hole in a workpiece, such as r a nut or the like.

Among other aims and objects of the invention may be recited the provision of mechanism of this character, wherein a hole or opening may be readily pierced in a workpiece without distortion of the exterior shape thereof; assure the stripping of the workpiece from the punch without damage thereto or to the punch; and to positively strip the slug, separatedfrom the blank, from engagement with the punch before the punch is'withdrawn from the workpiece.

The details and arrangement of the several parts and the method of their operation will be apparent from an inspection of the accompanying drawings in connection with the description hereinafter contained, and wherein a preferred embodiment of the invention is {disclosed for the purpose ofimparting an uncle standing of the same.

I Referring to the drawings, in which like numerals of reference indicate like parts in the several figures;

Figure 1 is a fragmentary sectional plan view of a portion of a machine of a conventional type used for forming workpieces, such as nuts or the like;

Figure 2 is a transverse sectional elevation thereof, taken generally upon line 2-2 of Fig ure 1;

Figure 3 is a View of the die and--associated parts;

Figure 4 is an enlarged view, similar to that shown in Figure 1, with the die and associated parts in their relative positions as the workpiece is about to pass out of engagement with the die and travel away therefrom;

Figure 5 is a transverse sectional view portion of the die, taken generally upon line 5-5 of Figure 3; and

Figure 6 is a perspective view of one of the wall members. a

If the hole or opening through the workpiece is not too large relatively it is pierced in the usual manner by projecting a punch therethrough while the workpiece is supported with one end face, either in whole or in part, against a rigid mem- 50 ber. In such case the exterior of the nut is not distorted. However, if the size of the hole is relatively large, thus leaving relatively thin walls surrounding the hole, the exterior of the workpiece is liable to be distorted to such a degree as 55 to make this method of piercing inadvisable. To

of a.

overcome this dimculty, workpieces whose exterior size and shape will be the same after the piercing operation as before, irrespective of the size of the opening or hole, and utilize the same type of machine, is a principal object of this invention. This desirable resultis obtained by piercing the workpiece while in a cavity that is substantially the same shape in cross section as the workpiece and withdrawing it therefrom while the area of the cavity is increased.

Combined with this mechanism is a device that strips the slug from the punch before the punch is withdrawn.

The disclosure is given by way of example, as one means of practicing the invention, which is not limited in any respect thereby.

The invention, as illustrated, is associated with either of those types of machine generally described as a header or upsetting machine and a press or the like, wherein one of a pair of cooperating tools is generally held in a fixed member and the other of the pairs of tools is generally mounted in a movable member. This application of the invention utilizes present forms of machines in general use.

Such parts of the conventional types of machine as are shown, comprise a frame 10, within which a die block 11 is fixed, the rear face of which contacts with a backing plate 12, and a gate 13, which has movement toward and away from the die block and carries a punch 14, held .known and constitutes no part of my present invention.

I-leld against movement within the die block 11 by the screw 18 is a die body 19, substantially cylindrical in form, having an enlarged head portion 20 with a plurality of radial slots 28, the T-head 29 of each of which has walls 30 that are at an angle to the axis of the die body and incline inwardly.

An anvil plate 26 fills the open space between the backing plate 12 and the rear of the die body 19, providing a rigid unyielding structure to withstand endwise pressure.

A die, axially movable within the die body, has an opening 22 which joins an opening 23 of larger" diameter. The die 21 and the parts associated therewith are held against rotation by apin 42 which is fast within the die body 19 and projects into a slot 43 in one wall of the die 21. Threaded in the die 21 is a sleeve 24, having a head 25 thereon, between which and the anvil plate 26 is a spring 27. y Within each of the slots 28 is a wall member 31, having a,T-head 32 and a body portion 33 of substantially the same width as the slot 28, with a face 34 slightly less in width than the body portion 33, but substantially the same as one of the faces of the workpiece. These wall members are slidable within the slots 38, and by reason of the angular walls 30 are moved toward and away from a common center as they are moved endwise in the die body 19. I

Whenthe wall members are in the inner position substantially as shown in Figure 3, each of the faces 34 provides one wall of a cavity 35 therebetween, the cross sectional shape of which is substantially the same as the workpiece. Each wall member has a. slot 36 between the body portion 33 and the tail-piece 37,'which latter pro- ;jects into an annular groove 38 in the die 21, 'and thus the outer exterior portion of the die 21 projects into the slot 36. Endwise movement ,of the die 21 imparts a like mpvement to all of the wall members.

Secured to the die body. 19 is a segment plate 39 which overlaps some of the wall members and limits axial movement of all the wall members. In Figures 1, 2, 3 and 5 the several parts are in position to receive a workpiece 40, which is projected therein by the punch until one face thereof contacts with the outer face of the die 21. Continued movement of the punch thereafter forces the same through the workpiece and separates a slug 41 therefrom, which ispro'jected into the opening 22, from which it passes into the opening 23, and in time escapes from the outer end of the sleeve 24, which has an opening therethrough of substantially the same size as the opening 23. From the sleeve 24 the slugs drop onto an inclined wall 48, which guides the slugs to a receptaclm conveniently arranged to receive them. During this operation the outer walls of the workpiece are in contact with the walls 34 of the cavity 35 and are held against enlargement or distortion.

During the piercing operation the rear face of the die 21 is in contact with the anvil plate 26,

thus forming a solid unyielding mass of metal.

to withstand the strain of the piercing operation. After the piercing operation the punch is movedaway from the die 21 and carries with it the workpiece 40 by reason of its frictional engagement on the reduced portion 15. At the beginning of this withdrawal motion the friction of the outer walls of the workpiece against the walls 34 of the cavity 35 is such that the wall members 31 and the die 21 travel therewith as a unit. During this movement, the wall members, by their engagement with the angularwalls 30, travel outwardly away from their common center, and the faces 34 thereon away from the faces of the workpiece, and thus enlarge the cross sectional area of the cavity 35. As the faces 34 move out of engagement with the workpiece, the latter is free .to travel with the punch out of the cavity. As the workpiece engages the stripper bushing 17 it is stripped from the punch in the open space between the die block 11 and the stripper bushing. When the workpiece is withdrawn from the cavity 35, the spring 27 moves the die 21 rearwardly until its rear face again engages the anvil plate 26. This rearward movement causes the wall members 31 to travel inwardly again toward the common center and restore the cavity 35 to the exterior size of the workpiece. The cavity illustrated is shaped for a hexagon workpiece but within the invention may be of any shape desired by varying the shape, and, if necessary, the number of the wallmembers.

The workpiece during the piercing operation is supported by a movable die and is contained within a cavity that prevents enlargement or distortion of the shape thereof. Thereafter the cavity is automatically enlarged, the workpiece is withdrawn therefrom, and the parts automatically restored to a position to receive the next workpiece.

If a liquid is used for the piercing operation, it may be drained ofi, if desired, through an opening 49 in the die block.

Heretofore there has been difliculty at times, depending upon the character of the metal and other things, in freeing the slug from the end of the punch, which, if it remains on the end oi. the punch, may damage workpieces and injure the tools.

Mechanism to insure the stripping ofthe slug from the punch comprises a stripper pin 44 movably mounted within the die 21, with its'rounded end adjacent to the opening 22. A pin 45 within the die body 19 bears against the head of the stripper pin 44 under the constant pressure of a and thus strips the slug therefrom. The slug so held is moved away from the stripper pin 44 by the slug cut from the next succeeding workpiece and is pushed beyond the stripper pin 44 into the opening 23 The head of the pin 44limits the inward position of the pin to one wherein the roundedi end thereof projects slightly into the opening 22 and provides also a surface sumciently large to permit relative movement of the die within the die body and still maintain contact with the pin 45.

The invention covers all forms of modifications coming within the scope of the appended claims.

What I claim is:

1."In mechanism of the character described; an axially movable die; a punch co-operating with the die; members, movable with the die and radially relative thereto, and providing a cavity that is bottomed by the die and which varies in size with the radial position of the members,-and within which to hold a workpiece in operative position relative to the die when the cavity is of a predetermined size and thereby prevent distortion of the workpiece during the action of the punch.

2. In mechanism of the character described; a movably mounted die; a punch co-operating with the die; members, movable with the die and radially relative thereto, and providing a cavity that is bottomed by the die, and which varies in size with the radial position of the members, and within which to hold a workpiece in operative position relative to the die when 'the cavity is of a predetermined size and thereby prevent distortion of the workpiece during the action of the punch,.said members being in position to receive a workpiece when the die is at the substantial limit of its rection.

3. In mechanism of the character described; an

movement in one diaxially movable die; a punch co-operating with -the die; members, movable with the die and radially relative thereto, and providing a cavity that is bottomed by the die and which varies in size with the radial position of the members, and within which to hold aworkpiece in operative position relative to the die when the cavity is of a predetermined size and thereby prevent distortion of the workpiece during the action of the punch, said members having an operative engagement with the die.

4. In mechanism of the character described; a die; a punch co-operatingwith the die; members having an intermeshing engagement with the die and movable in a path at substantially a right angle to the axis of the die and providing acavity that is bottomed by the die and which varies in /size with the radial position of the members, and within which to hold a workpiece in operative position relative to the die when the cavity is of a predetermined size and thereby prevent distortion of the workpiece during the action of the punch.

5. In mechanism of the character described; an axially movable die; a punch co-operating with the die; members, movable with the die and radially relative thereto, so arranged with the die that the inner faces of the members, when in one of their relative positions, forms a cavity with unbroken walls and bottomed bythe die, within which to hold a workpiece in operative position relative to the die and prevent distortion of the workpiece during the action of the punch.

6. In mechanism of the character described; an axially movable die; a punch co-operating with the die; members, movable with the die and radiallyrelative thereto and providing a cavity that is bottomed by the die and within which to hold a workpiece in operative position relative to the die, said die and members being i moved in one direction 'by the friction between I operative position relative to the die, said die and members being moved asa unit in one direction by the friction between the walls of the workpiece and those of the cavity, when the punch with the workpiece associated therewith is being withdrawn from the cavity and the members away from each other thereby enlarging the size of the cavity and thereby releasing the said friction.

,8. In mechanism of the character described; an axially movable die; a punch co-operating with the die; members, movable with the die; and providing a variable size cavity bottomed by the die and within which to hold a workpiece in operative position relative to the die, said die and members being moved as a unit in one direction by the friction between the walls of the workpiece and those of the cavity, when the punch with the workpiece associated therewith is being withdrawn from the cavity and the members away from each other thereby enlarging the size of the cavity; and means for moving the die and members, as a unit, when the friction between the workpiece and the walls of the cavity is reeased.

9. In mechanism of the character described; a movable die; an anvil member, against which the die abuts in one of its positions and forms a support to resist pressure; a punch co-operating with the die; members movable with the die and radially relative thereto and providing a cavity that is bottomed by the die and which varies in size with the radial position of the members, and within which to hold a. workpiece in operative position relative to the die when the cavity is of av predetermined size and thereby prevent distorticn of the workpiece during the action of the punch, the members, when the die is in contact with the anvil member, forming a cavity therebetween or substantially the same size and shape as the cross section of the workpiece.

10. In mechanism of the character described; a die; a punch co-operating with the die; members, movable with the die and radially relative thereto, that contact at their outer edges with fixed walls and thereby resist outward pressure, said members providing a cavitytherebetween that varies in size with the position of the members and is bottomed by the die, the walls of which form a rigid support for the workpiece when in the cavity and in operative engagement with the die.

11. In mechanism of the character described; a die; a. punch'co-operating with the die; mem-, bers movable with the die and radially relative thereto that provide a cavity that is bottomed by the die and which varies in size with the radial position of the members, and within which to hold a workpiece in operative position relative to the die when the cavity is of a predetermined size, said die forming a rigid support for the workpiece upon one face thereof and the members for the sides thereof.

12. In a punch and die mechanism, wherein the punch cuts a slug from the workpiece; means for applying friction to the slug to hold it against thereafter movement with the punch, said means projecting into the path of the slug, positioned so as to engage the slug while the same is on the punch, and yielding by reason of contact with the slug.

13. In a punch and die mechanism, wherein the punch cuts a slug from the workpiece; means for applying friction to the slug to hold it against thereafter movement with the punch, comprising a pressure member with a rounded nose that projects into the path of the slug while the same is in engagement with the punch, and means for applying a yielding pressure to said member.

14. In mechanism of the character described;

merit therein; a punch co-operating with the die for cutting a slug from a workpiece to form an opening therein; and means for applying friction to the slug to prevent it from traveling with the punch while being withdrawn from the workpiece, comprising a member in the die projecting into the path of travel of the slug, a second member within the die body having contact with the first member, and yielding means for applying pressure to said members.

, 15. In mechanism of the character described; a die body; a die having a reciprocating movement therein; a punch co-operating with the die for cutting a slug from a workpiece to form an opening therein; and means for applying friction to the slug to prevent it from traveling with the punch while being withdrawn from the workpiece, comprising a member in the die projecting into the path of travel of the slug, means for limiting '130 a die body; a die having a reciprocating move-.

opening tl'fiarein; and meansfor applying friction to the slug to prevent it from traveling with the punch while being withdrawn from the workpiece, comprising a member in the die projecting into the path of travel of the slug, means for limiting the extent of movement of said member, a second member within the die body having a limited inward movement and through which motion is imparted. to the iirst member in one direction, and

yielding means applying pressure to said members.

RICHARD LESTER WILCOX. 

